Letters archive

David Sloan Wilson's group-selection overview (Instant Expert, 6 August) points out the connection between the dominant individualistic trend in sociobiology for the past five decades and self-oriented western socio-economic thought. He could also have mentioned that rebellious minorities, often Marxist, put forward vigorous arguments against such reductionism in all the sciences, as well as philosophy. …

In your exploration of a future in which artificial intelligence takes over (23 July, p 40) it was suggested "the best case scenario would be that AIs provide a 'human reserve' for those who want to stay as they are". That would be nice, but would AIs be motivated to do so? Such benevolence would …

In popular literature written by pedlars of postmodern nonsense, Austrian logician Kurt Gödel is often said to have destroyed mathematical certainty with his incompleteness theorems – which say there will always be statements about sets or numbers that mathematics can neither verify nor disprove. As Richard Elwes points out in "Ultimate logic" (30 July, p …

My childhood in South Africa meant that your interview with the country's science minister, Naledi Pandor (16 July, p 25) , was of particular interest. Pandor's "brain drain" sentiments echo those of my relatives still in South Africa, who have been concerned about this for years. The term is used in various professions. However, family …

There are technical as well as political risks associated with geoengineering approaches to limit the impact of climate change (6 August, p 3) . If research shows that predicted temperature rises could be limited by geoengineering, it is likely there will be pressure to go ahead, with a corresponding reduction in pressure to limit emissions. …

Economist Samuel Bowles's study of the calorific costs of early ways of producing food (30 July, p 26) adds a valuable extra dimension to the debate on the emergence of agriculture. The decrease in physical stature and health in the transition from hunter-gathering to agriculture is well documented, so we must believe it. But present-day …

In "Mighty rover" (6 August, p 26) , NASA's Class 10,000 conditions for rover assembly were described as containing "fewer than 10,000 particles of 0.5 micrometres or larger... in every cubic foot of air". Has the loss of its Mars orbiter in 1999 taught NASA nothing about mixing metric and imperial units?

I was intrigued by the use of helminthic parasites to treat autoimmune diseases (6 August, p 6) , as some years ago I was infected with hookworm in Vietnam. I was quite ill and treated in hospital on my return to the UK. I have mild asthma which, while not too bad, is noticeable. For …

Alan Hewer's letter suggests that unlike hackers targeting big companies, no one would be sympathetic to a "burglar claiming to have only broken into your house to point out the inadequacy of your locks" (30 July, p 29) . This stands to reason only if one also accepts the inadequacy of Hewer's analogy. To remedy …

The engineering ideas for cooling subways, particularly the London Underground, did not address the impact of the late afternoon rush hour, when temperatures peak (6 August, p 38) . I suggest a modified train sent to the hottest station carrying coolant – tanks of compressed air at about 20 megapascals. The expansion of this air …

As a postscript to Richard Fisher's discussion of the perils of too much knowledge (30 July, p 39) , it was said of the Wright brothers that they achieved heavier-than-air flight because they had not been to university, and so did not know that it could not be done.